Abstract and Introduction
Abstract
Object: Subependymal giant cell astrocytomas (SEGAs) are a common manifestation of tuberous sclerosis (TS). These evolving tumors have a propensity to cause obstructive hydrocephalus, usually due to obstruction at the level of the foramen of Monro. Differentiating SEGAs from subependymal nodules (SENs) before obstruction occurs may improve the morbidity associated with these tumors. In this study the authors' aim was to determine imaging characteristics of proven tumors in a single-center pediatric population.
Methods: The authors retrospectively reviewed all records and images obtained in patients with TS in whom results of biopsy sampling had proven that their tumors were SEGAs. Time to presentation, signs and symptoms at presentation, and imaging characteristics of the evolving tumors were noted. Twelve patients with 14 SEGAs proven by the results of biopsy sampling were reviewed. Resection was recommended for symptomatic and neuroimaging evidence of hydrocephalus (41%), tumor growth without evidence of hydrocephalus (33%), and for poorly controlled seizures (25%). The mean diameter of the tumors at the time of resection was 1.9 cm (range 0.3-4 cm), and no tumor recurred. Because of the pathological and radiographic continuum of SENs and SEGAs, it remains difficult to predict whether and when a given lesion will progress. Tumor growth and contrast enhancement are the most common signs of progression on neuroimages, and may be seen prior to the development of obstructive hydrocephalus.
Conclusions: Patients with SENs and SEGAs should undergo follow-up neuroimaging at yearly intervals, and if lesions show signs of progression (contrast enhancement or growth), these intervals should be shortened and consideration given to early resection.
Introduction
Tuberous sclerosis is an autosomal-dominant, multisystem, neurocutaneous syndrome classically characterized by the Vogt clinical triad of seizures, mental retardation, and facial adenoma sebaceum. Benign tumors occur in various organs, including the heart, kidneys, and brain. In the brain, the lesions typically manifest as cortical and subependymal hamartomas or tubers; these are areas of giant neurons, astrocytes, and areas of gliosis.
A common manifestation of TS is the SEGA. Occurring in 5 to 10% of patients with TS, usually in the second decade of life, these lesions have been theorized to arise from subcortical tubers. Although histologically benign, SEGAs commonly arise in the lateral ventricles near the foramen of Monro and can result in obstructive hydrocephalus. Historically, patients often presented with symptoms of increased intracranial pressure, and the death rate after surgery in the acute phase approached 10%. More recently, tumors have been resected in the nonacute phase to improve prognosis.